1. Field of the Invention
The present invention concerns a rechargeable cell with spiral-wound electrodes, especially a lithium cell.
2. Description of the Prior Art
In a spiral-wound electrode cell the electrodes are in the form of strips spiral-wound around a central mandrel to form a cylinder. Each electrode comprises a metal current collector which supports the active material of the electrode on at least one of its faces. It is electrically connected to a current output terminal which provides electrical continuity between the electrode and the external application with which the cell is associated.
The terminal passes through the container of the cell: the part outside the container receives the external connections and the part inside it is connected to the electrodes. The terminal can be part of or attached to the container. When it is attached to the container, an electrically insulative seal is usually provided between said terminal and the container of the cell.
There are various ways to make the electrical connection between an electrode and a current output.
One way is to use a conductive blade member or thin metal strip: one end is welded to the edge of the collector, the other end being welded to the internal part of the terminal situated inside the container. For reasons of overall size, the blade member is generally fixed to the part of the collector nearest the axis of the spiral. A single blade member is sufficient for an electrode of low capacity, for example less than 5 ampere-hours, and a low power, for example less than 40 watts.
An aim of the invention is to propose a cell with spiral-wound electrodes, a high capacity and/or a high power.
An aim of the invention is to propose a lithium cell with spiral-wound electrodes, a high capacity and/or a high power.
By high capacity is meant a capacity greater than 20 ampere-hours. By high power is meant a power greater than 60 watts.